neither al qaeda in afghanistan nor pakistan now pose as grave a threat to america as their affiliate in somalia, that according to u.s. counterterrorism officials. the group known as al shabaab has even been successful in recruiting westerners. >> al shabaab is recruiting inside american mosques in somali communities like minneapolis and san diego according to the justice department. >> reporter: congressman peter king, chairman of the commtee on homeland security, held a hearing on the increasing threat. >> the terrorist training camps run by al shabaab teach their participants how to kill people and so the ability of one of those individuals to return to the united states and to put into practice that training is a threat. >> reporter: abc news has learned that before he died osama bin laden was secretly urging al shabaab to target the u.s. at least 40 somali-americans have trained and fought in a civil war in their homeland in the last three years, including three suicide bombers. as many as two dozen remain unaccounted for. >> probably the next, most significant terrorist threat